Customizable Responder Chain Category

NSObject+CustomMethod.m

#import "NSObject+CustomMethod.h"

typedef void(^SelectorBlock)(NSObject *responder);

@implementation NSObject (CustomMethod)
#pragma mark associative storage
- (NSObject *)spi_nextResponder
{
    NSObject *ao = objc_getAssociatedObject(self, _cmd);
    if (ao) {
        return ao;
    } else if ([self isKindOfClass:[UIResponder class]] && [self performSelector:@selector(nextResponder)] != nil) {
        return [self performSelector:@selector(nextResponder)];
    } else if ([self isKindOfClass:[UIViewController class]] && [self performSelector:@selector(parentViewController)] != nil) {
        return [self performSelector:@selector(parentViewController)];
    } else if ([self isKindOfClass:[UIView class]] && [self performSelector:@selector(superview)] != nil) {
        return [self performSelector:@selector(superview)];
    } else {
        return nil;
    }
}

- (void)setSpi_nextResponder:(NSObject *)spi_nextResponder
{
    objc_setAssociatedObject(self, @selector(spi_nextResponder), spi_nextResponder, OBJC_ASSOCIATION_ASSIGN);
}

#pragma mark  responder chain delegate
// performSelectorのメモリリークについての警告が出るが、これについてはAppleが無視してよいと回答しているため、無視する
// 参考：http://ameblo.jp/xcc/entry-11076019667.html
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Warc-performSelector-leaks"
- (void)spi_delegateSelector:(SEL)selector withObject:(NSObject *)object1 withObject:(NSObject *)object2
{
    [self spi_delegateSelector:selector selectorBlock:^(NSObject *responder) {
        [responder performSelector:selector withObject:object1 withObject:object2];
    }];
}

- (void)spi_delegateSelector:(SEL)selector withObject:(NSObject *)object
{
    [self spi_delegateSelector:selector selectorBlock:^(NSObject *responder) {
        [responder performSelector:selector withObject:object];
    }];
}

- (void)spi_delegateSelector:(SEL)selector
{
    [self spi_delegateSelector:selector selectorBlock:^(NSObject *responder) {
        [responder performSelector:selector];
    }];
}
#pragma clang diagnostic pop

- (void)spi_delegateSelector:(SEL)selector selectorBlock:(SelectorBlock)selectorBlock {

    NSObject *responder;
    responder = [self spi_nextResponder];

    // nextResponderを辿ってセレクタが実装されているコントローラが見つかったら
    // そのコントローラに処理させる。
    while (responder) {
        if ([responder respondsToSelector:selector]) {
            selectorBlock(responder);
            break;
        }
        responder = [responder spi_nextResponder];
    }
}
@end